Heat dissipating assembly with reduced thermal gradient

ABSTRACT

A device to dissipate thermal energy generated by a heat generating component. The device includes a base plate and a housing secured to and disposed on the base plate to form an enclosed space surrounded thereby. The device also includes a plurality of fins secured to the base plate and disposed in the space; an inlet pipe for introducing cooling fluid into the space and an outlet pipe for exhausting the cooling fluid from the space. The inlet pipe has a flow exit positioned over the fins so that the cooling fluid flows from the top portions of the fins toward the base plate.

BACKGROUND OF THE INVENTION

The present invention generally relates to devices for coolingelectrical components and, more particularly, to liquid cooledwaterblocks for dissipating heat energy.

With the advance of main unit's operation speed, the thermal energygenerated by active components of a computer, such as processor andmemory chip, often becomes significant. For instance, in order to enabledesktop and other computers to rapidly process graphics and gametechnology, add-on units generally referred to as “graphics cards” or“VGA” cards” are often installed in computer devices. Such cards includea separate processor, called a GPU, one or more memory chips, and otherrequired circuitry, all mounted to a circuit board including an edgeconnector that is adapted to plug into an available slot in theassociated computer device. Typically, GPU and/or memory chips generatessubstantial heat that if not dissipated will adversely affect operationof the graphics card.

Heretofore, various approaches have been tried to dissipate or otherwiseremove heat from the thermal energy generating components. FIG. 1 showsa conventional liquid cooled waterblock 100 for dissipating heat energygenerated by an active component. As depicted, the waterblock 100includes a top cover 102 and a body 104 sealingly secured to the topcover by a plurality of fasteners (not shown in FIG. 1) passing throughthe holes 106. The body 104 includes a channel 110 that forms apassageway for cooling liquid with the bottom surface of the top cover102. The waterblock 100 may be disposed on and in contact with a heatgenerating component so that the heat energy generated by the componentis conducted to the radiator 108 included in the body 104. The coolingfluid flows into the channel 110 via an inlet pipe 112, dissipate heatenergy from the radiator 108 and body 104, and exits the waterblock viathe outlet pipe 114.

As the cooling liquid flows through the channel 110 in one direction, athermal gradient may be established in the radiator 108 along the flowdirection, which may induce a similar thermal gradient in the heatgenerating component disposed under the radiator 108. The thermalgradient in the heat generating component may reduce the operationalperformance thereof and possibly shorten the life expectancy due to theheat damage on the lee side thereof. Furthermore, as the cooling liquidflows through the channel 110, the cooling liquid may be pre-warmedbefore reaching the radiator 108, reducing the efficiency in cooling theradiator 108. Thus, there is a need for an improved heat extraction ordissipation mechanism that can reduce the pre-warming of the coolingliquid and the thermal gradient of the heat generating component therebyto enhance the performance thereof.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a device for cooling a componentincludes: a base plate; a housing secured to and disposed on the baseplate to form an enclosed space surrounded thereby; a plurality of finssecured to the base plate and disposed in the space; an inlet pipe forintroducing cooling fluid into the space, the inlet pipe having a flowexit positioned over the fins; and an outlet pipe for exhausting thecooling fluid from the space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded perspective view of a conventional liquidcooled waterblock;

FIG. 2 shows a schematic perspective view of a liquid cooled waterblockin accordance with one embodiment of the present invention;

FIG. 3 shows a schematic cross sectional view of the waterblock in FIG.2, taken along the line III-III;

FIG. 4 shows a schematic cross sectional view of the waterblock in FIG.2, taken along the line IV-IV; and

FIG. 5 shows a schematic cross sectional view of a waterblock inaccordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplatedmodes of carrying out the invention. The description is not to be takenin a limiting sense, but is made merely for the purpose of illustratingthe general principles of the invention, since the scope of theinvention is best defined by the appended claims.

Referring to FIG. 2 of the drawing, a waterblock in accordance with oneembodiment of the present invention is illustrated at 200 and includes abase plate 204 and an upper cover or housing 202 sealingly secured tothe base. FIGS. 3 and 4 show schematic cross sectional diagrams of thewaterblock 200 in FIG. 2, taken along the lines III-III and IV-IV,respectively. Cooling fluid enters into the waterblock 200 through theinlet pipe 206 and exits through the outlet pipe 208. The cooling fluidis preferably water or any other suitable liquid or gas for dissipatingheat from the waterblock. For brevity, a pump for circulating thecooling fluid through the inlet/outlet pipes and a cooling system forextracting heat energy from the cooling fluid are not shown in FIG. 2.However, it should be apparent to those of ordinary skill that anysuitable conventional pump and cooling system may be used with thewaterblock 200.

The base plate 204 may be formed of heat conducting material, such asaluminum, copper, nickel, or any other suitable metal. The base plate204 can be mounted on a heat generating component 214 to extract heatenergy therefrom. The housing 202 may be formed of plastic that canstand the temperature of the cooling fluid. In one exemplary embodiment,the housing 202 may be injection molded polyoxymethylene (POM) plastic.The inlet pipe 206 and outlet pipe 208 can be connected to a pump (notshown in FIG. 2) by use of a conventional fitting, such as “F” fitting.

The waterblock 200 includes an upper chamber 212 and a lower chamber 213separated by a middle plate 216 having one or more openings 218 forfluid communication between the upper and lower chambers. The middleplate 216 may be formed of metal or plastic that can stand thetemperature of the cooling fluid. In one exemplary embodiment, themiddle plate 216 and housing 202 can be formed as an integral body.

Attached to the upper surface of the base plate 204 are a plurality offins 210, each fin having a dome-shaped top portion and acylinder-shaped bottom portion. The cylinder-shaped bottom portion mayhave various cross sectional shapes, such as hexagon, rectangle, circle,oval, or the like. The fins 210 operate as radiator, i.e., the heatgenerated by the heat generating component 214 is conducted to the fins210 via the base plate 204. The fins 210 may be formed of heatconducting material, such copper, aluminum, nickel, or the like, andarranged in a two-dimensional array format, for instance. The number,size, and arrangement of the fins 210 may be determined by variousdesign parameters, such as flow rate, pressure drop, and heat conductionrate.

The inlet pipe 206 extends through the upper chamber 212 to the lowerchamber 213, thereby introducing cooling fluid directly into the lowerchamber 213. The inlet pipe 206 has a flow exit positioned over the fins210 so that the cooling fluid exiting the inlet pipe 206 flows from thetop portions of the fins 210 toward the base plate 204, dissipating heatenergy from the fins 210 and base plate 204. The heated cooling fluidexits the lower chamber 213 to the upper chamber 212 through theopenings 218 and thence exits the upper chamber through the outlet pipe208.

It is noted that cooling fluid flows generally in radial directions whenseen from the top. Thus, the thermal gradient may be developed along thedistance, D, between the inlet pipe wall and edges of the base plate204. For a base plate having the same dimension as the radiator 108, thethermal gradient in the base plate 204 would be much smaller than thatof the radiator 108 since the distance D is much smaller than the lengthof the radiator 108.

It is also noted that the cooling fluid contacts the fins 210 as soon asit exits the inlet pipe 206. As such, the cooling fluid is notpre-warmed before reaching the fins 210, providing an improved coolingefficiency compared to the conventional waterblock 100.

In one exemplary embodiment, the fins 210 may be secured to the baseplate 204 by fasteners, such as bolts, or by suitable adhesive, such asthermal epoxy. In another exemplary embodiment, the fins 210 and baseplate 204 may be formed as an integral body. The base plate 204 may besecured to the heat generating component 214 by suitable thermal epoxy.The form factors of the waterblock 200 may be determined by variousparameters, such as the dimension of the heat generating component 214.It should be apparent to those of ordinary skill that the base plate 204may have a suitable shape, such as circle, and the housing 202 may alsohave a suitable shape, such as circular cylinder.

FIG. 5 shows a schematic cross sectional view of a waterblock 300 inaccordance with another embodiment of the present invention. Thewaterblock 300 may be similar to the waterblock 200, with the differencethat the inlet pipe 302 has a nozzle-shaped tip. The nozzle-shaped tipmay enhance flow uniformity over the top portions of the fins 306,thereby reducing the thermal gradient in the base plate 304.

Notwithstanding that the present invention has been described above interms of several alternative embodiments, it is anticipated that stillother alterations and modifications will become apparent to those ofordinary skilled in the art after having read this disclosure. It istherefore intended that such disclosure be considered illustrative andnot limiting, and that the appended claims be interpreted to include allsuch alterations, modifications and embodiments as fall within the truespirit and scope of the invention.

1. A device for cooling a component, comprising: a base plate; a housingsecured to and disposed on the base plate to form an enclosed spacesurrounded thereby; a plurality of fins secured to the base plate anddisposed in the space; an inlet pipe for introducing cooling fluid intothe space, the inlet pipe having a flow exit positioned over the fins;and an outlet pipe for exhausting the cooling fluid from the space.
 2. Adevice as recited in claim 1, further comprising: a middle plateseparating the space into upper and lower chambers and including one ormore openings for fluid communication therebetween, wherein the inletpipe extends through the upper chamber to the lower chamber and theoutlet pipe is operatively coupled to the upper chamber and the fins aredisposed in the lower chamber.
 3. A device as recited in claim 1,wherein each said fin includes a dome-shaped top portion and acylinder-shaped bottom portion.
 4. A device as recited in claim 3,wherein a cross section of the cylinder-shaped bottom portion has ashape selected from the group consisting of circle, oval, hexagon, andrectangle.
 5. A device as recited in claim 1, wherein the flow exit ofthe inlet pipe has an expanding nozzle shape.
 6. A device as recited inclaim 1, wherein the base plate is formed of heat conducting material.7. A device as recited in claim 6, wherein the heat conducting materialis selected from the group consisting of aluminum, copper, and nickel.8. A device as recited in claim 1, wherein the fins are formed of heatconducting material.
 9. A device as recited in claim 8, wherein the heatconducting material is selected from the group consisting of aluminum,copper, and nickel.
 10. A device as recited in claim 1, wherein thehousing is formed of plastic.
 11. A device as recited in claim 1,further comprising: a pump coupled to the inlet and outlet pipes andoperative to circulating the cooling fluid through the inlet and outletpipes.
 12. A device as recited in claim 1, further comprising: a coolingsystem coupled to the inlet and outlet pipes and operative to extractheat energy from the cooling fluid.